Algorithmic decision-making plays an important role in financial markets. Current tools in trading focus on popular companies which are discussed in thousands of news items. However, it remains unclear whether methodologies from the field of data analytics relying on large samples can also be applied to small datasets of less popular companies or whether these methodologies lead to the discovery of meaningless patterns resulting in economic losses. We analyze whether the impact of media sentiment on financial markets is influenced by two levels of investor attention and whether this impacts algorithmic decision-making. We find that the influence differs substantially between news and companies with high and low investor attention. We apply a trading simulation to outline the practical consequences of these interrelations for decision support systems. Our results are of high importance for financial market participants, especially for algorithmic traders that consider sentiment for investment decision support.
A number of critiques have been published drawing attention to the gaps in research methods applied to issues surrounding homelessness and service utilisation in Britain. This paper discusses the use of social identity, a theory drawn from the field of applied social psychology, and synthesises it with the pathways model, thereby providing a framework to further explore service utilisation. The synthesised framework was used to predict the uptake of outreach services in a prospective study of 121 homeless people in a major UK city. In general, homeless people's use of intervention services was affected by the extent to which they identified with the support services themselves. The study demonstrates the central role of social identity in understanding service utilisation patterns, and shows the importance of applying fresh techniques to fine-tune our understanding of uptake in the long term. 相似文献
CCR5, a chemokine receptor expressed on T cells and macrophages, is the principal coreceptor for M-tropic HIV-1 strains. Recently, we described an NH2-terminal modification of the CCR5 ligand regulated on activation, normal T cell expressed and secreted (RANTES), aminooxypentane-RANTES (AOP-RANTES), that showed potent inhibition of macrophage infection by HIV-1 under conditions where RANTES was barely effective. To investigate the mechanism of AOP-RANTES inhibition of HIV infectivity we examined the surface expression of CCR5 using a monoclonal anti-CCR5 antibody, MC-1. We demonstrate that AOP-RANTES rapidly caused >90% decrease in cell surface expression of CCR5 on lymphocytes, monocytes/ macrophages, and CCR5 transfected Chinese hamster ovary (CHO) cells. RANTES also caused a loss of cell surface CCR5, although its effect was less than with AOP-RANTES. Significantly, AOP-RANTES inhibited recycling of internalized CCR5 to the cell surface, whereas RANTES did not. When peripheral blood mononuclear cells are cultured for prolonged periods of time in the presence of RANTES, CCR5 expression is comparable to that seen on cells treated with control medium, whereas there is no CCR5 surface expression on cells cultured in the presence of AOP-RANTES. Immunofluorescence indicated that both AOP-RANTES and RANTES induced downmodulation of cell surface CCR5, and that the receptor was redistributed into endocytic organelles containing the transferrin receptor. When RANTES was removed, the internalized receptor was recycled to the cell surface; however, the receptor internalized in the presence of AOP-RANTES was retained in endosomes. Using human osteosarcoma (GHOST) 34/CCR5 cells, the potency of AOP-RANTES and RANTES to inhibit infection by the M-tropic HIV-1 strain, SF 162, correlated with the degree of downregulation of CCR5 induced by the two chemokines. These differences between AOP-RANTES and RANTES in their effect on receptor downregulation and recycling suggest a mechanism for the potent inhibition of HIV infection by AOP-RANTES. Moreover, these results support the notion that receptor internalization and inhibition of receptor recycling present new targets for therapeutic agents to prevent HIV infection. 相似文献
Quantitative classification of Landsat Thematic Mapper (TM and ETM+) imagery can provide a very useful medium for showing urban change at a watershed scale. It shows both the nature and the degree of urbanization with a resolution equivalent to that of the original TM image. Estimates of urbanization-related factors such as surface imperviousness and canopy cover can be coupled to illustrate the process of urban growth in the watershed using change vector analysis. When used together and combined with standard GIS data sets such as digital line graphs and digital elevation models, quantitative classification can provide the parameters needed to run standard hydrological models that can be used to describe or to forecast the effects of urbanization on area streams. Watersheds provide a meaningful scale for the analysis of the connections between urbanization and the environmental changes it brings. The study area for this paper is the Tinker's Creek watershed in northeast Ohio, USA. Tinker's Creek is one of the largest and most varied watersheds in the area, and it is subject to significant urbanization stress. Urbanization in the watershed is reflected in four TM images of northeast Ohio over a 15-year period (1984-1999). Quantitative classification provides a rich and detailed picture of urbanization over the time period of the study. 相似文献
Radon gas, which is the main contributor to human radiation exposure, is easily dissolved in, and dissipated from, water. Problems with radon occur because, in addition to being ingested, it (a) becomes attached to particles which lodge in the lungs and (b) emits alpha radiation. Concentration has been found to increase inversely with the size of a water supply. Although of little problem in mains'water, private water supplies in the UK have been found to contain more than ten times the recommended US levels. Despite this, very little monitoring is carried out for radon in private supplies. Local authorities, situated in areas where the geological conditions are such that high levels of radon would be expected, should carry out a suitable sampling and monitoring programme of their private water supplies. 相似文献
Although housing management as an occupational role has existed for over a century it has never received an adequate definition, and its scope and emphasis have varied over time. This paper locates housing management within the debates on the nature of the professions and bureaucracy, and suggests that these analyses are inadequate. It is proposed that a more fruitful approach in understanding the nature of housing management is derived from a consideration of its ‘social construction’. In support of this interpretation material from qualitative empirical research with practitioners is presented and analysed. Key respondents were identified as people working at the boundaries of housing management, such as in a caring or support role, since it was felt that the perceptions of such boundaries were important in defining the limits and limitations of housing management. In conclusion it is suggested that this is a critical moment for housing management in terms of achieving a more rigorous definition of its activities, and of seeking to resolve the conflict between the pressures to organise around commercial objectives and to provide a welfare service. Meanwhile there remains a somewhat paradoxical situation in that whilst the lack of consistent practice within housing management weakens its claims to occupational strength and legitimacy, these same inconsistencies permit individual practitioners the flexibility to offer a more responsive service to those in need. 相似文献
The aim of this article is to review the ways in which subjective well-being has been conceptualized within housing research, with a view to evaluating the use of the concept, the insights it has generated, the problems that have been experienced and the possible range of lessons that might be taken forward. The article begins with an analysis of the reasons why subjective well-being has become popular as a conceptual tool in many fields. The article continues with a discussion of the range of definitions that appear in the literature which leads into discussions of the research techniques and methodologies that have been used in empirical research. Empirical studies which focussed on the impact of physical housing conditions and tenure on subjective well-being are reviewed in order to evaluate what is known about the impact of housing on both personal and collective subjective well-being. This review highlights issues of status, reference groups and adaptation that are important insights from the subjective well-being approach that should set the agenda for further research in this area. The conclusion is that the relationship between housing and subjective well-being is a complex one that repays further study in order to understand the rich texture of the role of housing in people’s lives. The article concludes with suggestions for both conceptual and methodological approaches and the focus of future research. 相似文献
GIRK1 and GIRK4 subunits combine to form the heterotetrameric acetylcholine-activated potassium current (IKACh) channel in pacemaker cells of the heart. The channel is activated by direct binding of G-protein Gbetagamma subunits. The GIRK1 subunit is atypical in the GIRK family in having a unique ( approximately 125-amino acid) domain in its distal C terminus. GIRK1 cannot form functional channels by itself but must combine with another GIRK family member (GIRK2, GIRK3, or GIRK4), which are themselves capable of forming functional homotetramers. Here we show, using an extracellularly Flag-tagged GIRK1 subunit, that GIRK1 requires association with GIRK4 for cell surface localization. Furthermore, GIRK1 homomultimers reside in core-glycosylated and nonglycosylated states. Coexpression of GIRK4 caused the appearance of the mature glycosylated form of GIRK1. [35S]Methionine pulse-labeling experiments demonstrated that GIRK4 associates with GIRK1 either during or shortly after subunit synthesis. Mutant and chimeric channel subunits were utilized to identify domains responsible for GIRK1 localization. Truncation of the unique C-terminal domain of Delta374-501 resulted in an intracellular GIRK1 subunit that produced normal IKACh-like channels when coexpressed with GIRK4. Chimeras containing the C-terminal domain of GIRK1 from amino acid 194 to 501 were intracellularly localized, whereas chimeras containing the C terminus of GIRK4 localized to the cell surface. Deletion analysis of the GIRK4 C terminus identified a 25-amino acid region required for cell surface targeting of GIRK1/GIRK4 heterotetramers and a 25-amino acid region required for cell surface localization of GIRK4 homotetramers. GIRK1 appeared intracellular in atrial myocytes isolated from GIRK4 knockout mice and was not maturely glycosylated, supporting an essential role for GIRK4 in the processing and cell surface localization of IKACh in vivo. 相似文献